基于AD-AS模型的海岸带生态系统综合承载力评估——以舟山海岸带为例

以舟山海岸带为研究区域,结合采样数据和社会经济发展数据,构建以社会因子、经济因子和自然因子为3个维度因子的海岸带生态系统综合承载力评估的指标体系。并参照经济学中的AD-AS模型,改进成综合总供给-综合总需求模型(SAD-SAS模型),根据生态系统中总供给与总需求之间的平衡关系,来计算舟山海岸带综合承载力量值,并尝试将海岸带综合承载力值的分类标准在原来的基础上分为5类,最后评价其所处的承载力水平。研究结果表明:舟山海岸带综合承载力在2005—2008年时处于微幅上升的阶段,年均增速为6.5%,在2008—2009年开始出现稍微的下降,下降幅度为3%;SAD-SAS模型作为生态学与经济学交叉的模型,为海岸带综合承载力评价提供了一种新思路。     

西藏生态足迹与承载力动态分析

利用生态足迹模型,对2005—2010年西藏的生态足迹和生态承载力以及生态盈余进行了测算。研究发现,西藏2005—2010年人均生态足迹呈现出振荡式上升趋势,从2005年的0.34 hm2/人波动上升到2010年的0.83 hm2/人,其中人均林地消费所占比重最大,多年平均值占总消费的39.8%;人均耕地消费基本稳定在0.18—0.2 hm2/人之间,其他类型土地消费所占比重相对较少;人均生态承载力呈现平滑下降趋势,从2005年的14.78 hm2/人下降到了2010年的13.77 hm2/人,其中林地和牧草地及其转换的化石能源地人均生态承载力所占比重达到了95%,可耕地、牧草地、林地的人均生态承载力在2005—2010年之间呈现缓慢下降趋势,水域人均生态承载力变化不大;人均生态盈余较大,但呈现出递减趋势,2005年为14.44 hm2/人,而2010年下降到12.94 hm2/人;生态盈余中比重最大的是林地,但其足迹波动较大,介于1%—30%之间;草地人均生态足迹仅占生态承载力的5%左右,水域人均生态足迹占生态承载力的比例可忽略不计。     

鄱阳湖生态经济区资源环境综合承载力评价

随着社会经济的发展,人口、资源与环境之间的矛盾日趋加剧.因此,资源环境承载力问题成为各国（地区）政府所关注的焦点问题之一.本文通过对鄱阳湖生态经济区内资源、环境的现状及问题进行调查分析,选取土地资源、水资源、生物资源、矿产资源、生态-地质环境、水环境及大气环境作为评价准则层,在对上述7个单因素进行评价基础之上,以县（市、区）为评价单位,采用状态空间法对全区的资源环境承载力进行综合评价.结果表明：当前全区内生物资源较丰富,大气、水环境质量良好,地质环境整体较稳定,制约因素主要为土地资源、水资源和矿产资源;全区资源环境承载力表现为可载状态,但部分县（市、区）表现为超载状态.利用状态空间法进行区域资源环境综合承载力研究是可行的,具有意义明确、评价精度高等优点,可为区域资源环境综合承载力评价提供另一种途径.     

Increasing breadth of the frontal lobe but decreasing height of the human brain between two Chinese samples from a Neolithic site and from living humans

Morphological observation and measurements of endocasts have played a vital role in research on the evolution of the human brain. However, endocasts have never been used to investigate how the human brain has evolved since the Neolithic period. We investigated the evolution of the human brain during the Holocene by comparing virtual endocasts from Beiqian site (a Neolithic Chinese site) and a sample of Chinese modern‐day humans. Standardized measurements and indices were taken to provide quantification of the overall endocast shape, including the length, breadth, height, frontal breadth, and the ratio of frontal breadth to breadth, as well as the cranial capacity. We found that the height of the endocasts and cranial capacity have decreased between our two samples, whereas the frontal breadth and sexual dimorphism have increased. We argue that these changes can be caused by random genetic mutation and epigenetic change in response to changes in the environment. Am J Phys Anthropol 154:94–103, 2014. © 2014 Wiley Periodicals, Inc.     

Epigallocatechin gallate counteracts oxidative stress in docosahexaenoxic acid-treated myocytes

Skeletal muscle is a key organ of mammalian energy metabolism, and its mitochondria are multifunction organelles that are targets of dietary bioactive compounds. The goal of this work was to examine the regulation of mitochondrial dynamics, functionality and cell energy parameters using docosahexaenoic acid (DHA), epigallocatechin gallate (EGCG) and a combination of both in L6 myocytes. Compounds (at 25 μM) were incubated for 4 h. Cells cultured with DHA displayed less oxygen consumption with higher ADP/ATP ratio levels concomitant with downregulation of Cox and Ant1 gene expression. The disruption of energetic homeostasis by DHA, increases intracellular reactive oxygen species (ROS) levels and decreases mitochondrial membrane potential. The defence mechanism to counteract the excess of ROS production was by the upregulation of Ucp2, Ucp3 and MnSod gene expression. Moreover myocytes cultured with DHA had a higher mitochondrial mass with a higher proportion of large and elongated mitochondria, whereas the fission genes Drp1 and Fiss1 and the fusion gene Mfn2 were downregulated. In myocytes co-incubated with DHA and EGCG, ROS levels and the adenosine diphosphate (ADP)/adenosine triphosphate (ATP) ratio were similar to untreated myocytes and the decrease of oxygen consumption, higher mitochondrial mass and the overexpression of Ucp2 and Ucp3 genes were similar to the DHA-treated cells with also a higher amount of mitochondrial deoxyribonucleic acid (DNA), and reduced Drp1 and Fiss1 gene expression levels. In conclusion the addition of EGCG to DHA returned the cells to the control conditions in terms of mitochondrial morphology, energy and redox status, which were unbalanced in the DHA-treated myocytes.     

Climate sensitivity across marine domains of life: limits to evolutionary adaptation shape species interactions

Organisms in all domains, Archaea, Bacteria, and Eukarya will respond to climate change with differential vulnerabilities resulting in shifts in species distribution, coexistence, and interactions. The identification of unifying principles of organism functioning across all domains would facilitate a cause and effect understanding of such changes and their implications for ecosystem shifts. For example, the functional specialization of all organisms in limited temperature ranges leads us to ask for unifying functional reasons. Organisms also specialize in either anoxic or various oxygen ranges, with animals and plants depending on high oxygen levels. Here, we identify thermal ranges, heat limits of growth, and critically low (hypoxic) oxygen concentrations as proxies of tolerance in a meta‐analysis of data available for marine organisms, with special reference to domain‐specific limits. For an explanation of the patterns and differences observed, we define and quantify a proxy for organismic complexity across species from all domains. Rising complexity causes heat (and hypoxia) tolerances to decrease from Archaea to Bacteria to uni‐ and then multicellular Eukarya. Within and across domains, taxon‐specific tolerance limits likely reflect ultimate evolutionary limits of its species to acclimatization and adaptation. We hypothesize that rising taxon‐specific complexities in structure and function constrain organisms to narrower environmental ranges. Low complexity as in Archaea and some Bacteria provide life options in extreme environments. In the warmest oceans, temperature maxima reach and will surpass the permanent limits to the existence of multicellular animals, plants and unicellular phytoplankter. Smaller, less complex unicellular Eukarya, Bacteria, and Archaea will thus benefit and predominate even more in a future, warmer, and hypoxic ocean.     

In vitro cultivation of donor quince shoots affects subsequent morphogenesis in leaf explants

The effect of in vitro cultivation of donor shoots on subsequent morphogenesis in leaf explants of quince (Cydonia oblonga Mill.) clone BA29 was investigated. Proliferating donor shoots were cultured in ventilated or closed vessels under different photosynthetic photon flux densities (PPFD; 200 and 100 μmol m⁻² s⁻¹) with 0, 15, 30 g dm⁻³ sucrose. Shoots grown in ventilated vessels, especially with sucrose at 15 or 30 g dm⁻³, were better developed with fully expanded leaves compared to those in standard closed vessels. Leaves collected from pre-treated donor shoots were used to assess regeneration capacity. Somatic embryo production was highest in leaves harvested from shoots cultured in closed vessels with 30 g dm⁻³ sucrose and in ventilated vessels with 15 and 30 g dm⁻³ sucrose and under high PPFD which was, in comparison with the control treatment (closed vessel, 30 g dm⁻³ sucrose and low PPFD), about 2 to 2.5 times higher. A similar response was observed for root regeneration.     

Evaluation of the copper(II) reduction assay using bathocuproinedisulfonic acid disodium salt for the total antioxidant capacity assessment: The CUPRAC-BCS assay

There is heightened interest in determining antioxidant status of individuals in experimental and clinical studies investigating progression of diseases or diverse aspects of oxidative stress, among others. The aim of this study was to evaluate the copper(II) reduction assay with bathocuproinedisulfonic acid disodium salt as chelating agent (the CUPRAC-BCS assay) for the total antioxidant capacity (TAC) assessment in human plasma and urine. Samples from 20 individuals were determined with four spectrophotometric assays—CUPRAC-BCS, ferric reducing ability of plasma (FRAP), trolox equivalent antioxidant capacity (TEAC), and 1,1-diphenyl-2-picrylhydrazyl assay (DPPH)—to compare these methods. CUPRAC-BCS was significantly correlated with FRAP and TEAC for plasma and urine samples (r > 0.5, P < 0.05 for all) and with DPPH for urine samples (r = 0.925, P < 0.001) but not with DPPH for plasma samples (r = 0.366, P = 0.112). However, the four methods do not agree given that lines of equality and regression were not matched up. The imprecision of the method is less than 6%, the detection limit is 41.8 μmol trolox equivalents/L, it is linear up to 2 mM trolox, and ethylenediaminetetraacetic acid dihydrate disodium salt (EDTA) binds to Cu(II), avoiding the formation of Cu(I)-BCS complex. This study shows that CUPRAC-BCS is a simple, fast, inexpensive, and suitable method for TAC assessment in human urine and heparinized plasma samples.